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Ames Laboratory

Quantum Physics

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Articles 1 - 8 of 8

Full-Text Articles in Physics

Angular Distribution Of Photoprotons From Aluminum And Tantalum, Marvin M. Hoffman, D. J. Zaffarano Aug 1952

Angular Distribution Of Photoprotons From Aluminum And Tantalum, Marvin M. Hoffman, D. J. Zaffarano

Ames Laboratory ISC Technical Reports

The study of those nuclear reactions which occur as a result of x-ray irradiation has been greatly facilitated by the increasing availability of high energy betatrons and synchrotrons. On occasion radioactivity may be induced in irradiated nuclei and in these cases it is possible to conclude that either a new element or an isotope of the bombarded nucleus has been formed. Since the nature of the radiation from many unstable nuclei is well known, a study of the type and energy of the emitted particles and the period of radioactive decay will usually suffice to determine which nucleus has been ...


High Specific Radioactivites Of Cobalt, Platinum, And Iridium From Photonuclear Reactions, Darleane Christian, Don S. Martin Jr. Dec 1951

High Specific Radioactivites Of Cobalt, Platinum, And Iridium From Photonuclear Reactions, Darleane Christian, Don S. Martin Jr.

Ames Laboratory ISC Technical Reports

The attainment of high specific activities is an important requirement for the detect i on and utilization of radioactivities produced by photonuclear reactions. If an element different from the target element is produced suitable chemical procedures for the separation of the radioactive atoms from the target atoms can usually be found. However, finding rapid and efficient methods for separating isotopes of the target element formed by the (y,n) reaction presents a more difficult problem. To facilitate the study of the properties of cobalt and platinum actiities produced in the synchrotron by (y,n) reactions, an attempt was made to ...


New Technique For Measuring Photonuclear Cross Sections And Its Applications To The Cu-63(Y,N)Cu-62 And C-12(Y,N)C-11 Reactions, Lester L. Newkirk, L. Jackson Laslett Dec 1951

New Technique For Measuring Photonuclear Cross Sections And Its Applications To The Cu-63(Y,N)Cu-62 And C-12(Y,N)C-11 Reactions, Lester L. Newkirk, L. Jackson Laslett

Ames Laboratory ISC Technical Reports

A new technique for the determination of photonuclear cross sections is described in detail. It was applied to the CU-63(y,n)CU-62 and C-12(y,n)C-11 reactions from thresholds up to 60 Mev. The results obtained are consistent and are in good agreement with results obtained by different methods (1,2).


Cloud Chamber Identification Of Photodeuterons From Copper, Warren H. Smith, L. Jackson Laslett Dec 1951

Cloud Chamber Identification Of Photodeuterons From Copper, Warren H. Smith, L. Jackson Laslett

Ames Laboratory ISC Technical Reports

Evidence has been reported (1,2) for the production of deuterons in the disintegration of copper and sulfur by bromsstrahlung before 24 Mev. energy. In the more direct of these investigations (1), the presence of a deuteron group was inferred on the basis of range and grain-density measurement in nuclear emulsions, and led to a ratio of photodeuterons to photoprotons cited as 0.31 for copper. Due to the bearing which such a large deuteron group must have on the theory of photonuclear processes, an independent investigation of the photodeuteron yield from copper was undertaken.


The Beta-Spectra Of P-32 And P-33, Erling N. Jensen, R. T. Nichols, J. Clement, A. Pohm Aug 1951

The Beta-Spectra Of P-32 And P-33, Erling N. Jensen, R. T. Nichols, J. Clement, A. Pohm

Ames Laboratory ISC Technical Reports

The beta-spectrum of P-32 has been examined with a thin-lens spectrometer. The maximum energy of the 14.3-day beta activity, as determined from several Kurie plots, was found to be 1.704 +/- 0.008 Mev. The Kurie plots gave excellent straight lines from the maximum beta-energy to about 0.26 Mev. In phosphorus samples prepared from neutron irradiated sulfur an additional beta-activity was observed having a maximum energy of 0.26 +/- 0.02 Mev and a half-life of 24.8 +/- 0.5 days. This low-energy beta-group was also observed in phosphorus samples prepared from sulfur and lithium chloride irradiated with ...


Short-Lived Synchrotron-Induced Radioactivities, Forrest I. Boley, D. J. Zaffarano Jul 1951

Short-Lived Synchrotron-Induced Radioactivities, Forrest I. Boley, D. J. Zaffarano

Ames Laboratory ISC Technical Reports

The use of a scintillation spectrometer for measurement of the energy distribution and half-life of short-lived beta-emitters is described. The instrumentation is especially suited for use with radioactivities of low intensity resulting from photonuclear reactions produced by the Iowa State College 70-Mev synchrotron. Such activities are unsuited for study with a conventional magnetic spectrometer of small solid angle, particularly if the activities are short-lived, but may readily be analyzed with a scintillation spectrometer, for which the solid angle of acceptance is close to 50 per cent.


Cloud Chamber Measurement Of Electron Pairs For Determination Of Synchrotron Spectrum, Richard H. Stokes, L. Jackson Laslett Jun 1951

Cloud Chamber Measurement Of Electron Pairs For Determination Of Synchrotron Spectrum, Richard H. Stokes, L. Jackson Laslett

Ames Laboratory ISC Technical Reports

The x-ray spectrum of the Iowa State College synchrotron operating at 65 Mev. has been measured. The method consisted of the observation, in a magnetic cloud chamber, of the momentum of each member of electron pairs produced in the air filling of the chamber. Using the theoretical values of cross section for pair production and the results of recent experiments, the energy spectrum of the x-ray quanta was computed. Due to the pronounced forward directional characteristic of electron pairs produced at extreme relativistic energies, discrimination of one energy region with respect to another was avoided and no solid angle corrections ...


Some Synchrotron Produced Radioactivities Of Tantalum, Alfred J. Moses, Don S. Martin Dec 1950

Some Synchrotron Produced Radioactivities Of Tantalum, Alfred J. Moses, Don S. Martin

Ames Laboratory ISC Technical Reports

X-ray irradiation of wolfram by a synchrotron beam have produced three radioactive isotopes of tantalum with half-lives of 48 m. (TA-185), 8.0 hr. (TA-180) and 6.0d (TA-183) Characteristics of the activities have been studied by absorption and coincidence measurements. Separated W-182 was used for the identification of the TA-180. Relative yields of the three isotopes were measured for beam energies of 30 Mev. and 68 Mev. In addition, the yields for 68 Mev. have been compared to the yield of the reaction C-12(y,n) C-11. TA-180 can not form by a (y, p) reaction; however its yield ...